Antiperspirants

ABSTRACT

A PROCESS FOR THE PREPARATIONOF A NOVEL ALUMINIUM HYDOROXYCHLORIDE COMPOUND WHICH MAY BE USED AS ANTIPERSPIRANTS USED FOR THE PREPARATION FO COSMETICS.

Oct. 16, 1973 KAzgHlRo TsuKADA n 3,766,233

ANTIPERSPIRANTS' Filed Dec. l5. 1971 l l l I I United States Patent O U.S. Cl. 260-448 R 7 Claims ABSTRACT OF THE DISCLOSURE A process for the preparation of a novel aluminium hydroxychloride compound which may be used as antiperspirants used for the preparation of cosmetics.

This invention relates to a novel complex compound consisting of aluminium hydroxychloride, known as an antiperspirant, and terpenoids.

Aluminium hydroxychloride, known as elfective antiperspirants, has a serious defect that it is hardly soluble in auxiliary solvents such as absolute alcohols and propellants normally used in aerosols. Thus, an aerosol antiperspirant of the powdered suspension type has been proposed (Japanese patent publication No. 798/70) but, in this case, there is a serious risk that the aerosol of the powdered suspension type will give rise to gas leakage and valve clogging.

In order to make aluminium hydroxychloride soluble in absolute alcohol, it is known to prepare its complex compound with glycols (U.S. Pat. No. 3,420,932), or with polyhydroxy compounds (British Pat. No. 1,009,959) or with phenolsulfonic acid or its salts (Japanese patent publication No. 22,437/ 70). These complex compounds, however, are not entirely satisfactory as they are apt to attack metallic vessels.

Thus, the solution type aerosol cosmetics containing aluminium hydroxychloride has not been up to now available commercially.

The primary object of the present invention is to provide an aluminium hydroxychloride compound which can be dissolved in ethanol or other organic solvents in higher concentrations and which is less corrosive to metallic vessels. Other object of the present invention is to provide a solution type aerosol antiperspirant containing aluminium hydroxychloride compound in an effective concentration.

As a result of our researches aimed to attain these objects, it has been discovered that a novel complex compound of aluminium hydroxychloride less corrosive to metallic vessels can be prepared by reacting aluminium hydroxychloride with terpenoids, such as hydroxycitronellal, cyclamen aldehyde, geraniol, linalool, geranyl acetate, and l-menthol, which are non-polar, oleophilic and sparingly soluble in water to a higher extent than the known glycols, polyhydroxy compounds, or phenolsulfonic acids and their salts.

This novel complex compound can be dissolved in absolute or aqueous alcohols and therefore can be used effectively for the preparation of cosmetics of the perspiration inhibitive type in the form of aerosols, roll-ons, sticks, pastes, jelly and cream. Above all, since absolute alcohol is compatible or mutually soluble with liqueed chlorouorohydrocarbons, it is especially convenient for the preparation of aerosol antiperspirants.

The present invention will be more clearly understood by the following description and the drawing attached hereto in which:

FIG. 1 is a chart showing infrared absorption spectrum characteristics proper to the complex compound of the present invention.

i Patented Oct. 16, 1973 ICC In preparing the novel complex compound according to the present invention, a given amount of aluminium hydroxychloride is dissolved in water to give an aqueous solution containing aluminium hydroxychloride in a desired concentration, preferably an aqueous solution containing 50 wt. percent of aluminum hydroxychloride. Then, the terpenoid, such as hydroxycitronellal, is added in an amount necessary to produce a complex compound having the desired molar ratio. Then, the lower alcohols, such as methanol, ethanol or isopropanol, are added in sufficient amounts to produce a homogeneous solution. Thesolution thus obtained is heated to a temperature of 40 to 120 C. under reduced pressure of 60 to 100 mm. Hg. The complex compound can then be isolated upon elimination of the solvents.

The complex compound thus obtained is then pulverized and dried into a stable powdered porduct. The product thus formed is ready for practical usage when dissolved in alcohol or other solvents. If necessary, the powdered product can be further purified through recrystallization and other known processes.

The molar ratio of the terpenoid and the aluminium hydroxychloride contained in the thus obtained complex compound can be varied within a range of 1 mole of terpenoid to 1 to 12 moles of aluminium hydroxychloride. It is to be noted that the complex compound of the aluminium hydroxychloride and the terpenoid prepared in this way contains 2 to 4 moles of bound water.

The novel @complex compound can be dissolved in higher concentrations in absolute alcohols, aqueous alcohols, denaturated alcohols, isopropanol, n-butanol, propylene glycol and glycerine and can be used as highly effective astringents for the preparation of cosmetics with the property of inhibiting perspiration. Above all, since the above-mentioned solution containing the novel complex compound in a higher concentration is compatibile or mutually soluble With chlorofluorohydrocarbons and other materials used as aerosol propellants, it can be used conveniently for the preparation of aerosol cosmetics having the property of inhibiting perspiration. As an example, the 20% solution of the present complex compound in absolute alcohol is miscible with trichloromonofluoroethane, dichlorofluoroethane, dichlorotetrauoroethane, vinyl chloride, dimethyl ether or liqueiied petroleum gases, which are employed in aerosols as propellants.

There is no specific limitation to the aluminium hydroxychloride used for the preparation of the present novel complex compound, and the ratio of aluminium to chlorine can be varied within the range of theoretical limitation. A marketed product of the rational formula of Al2(OH)5Cl. 11H20 is, however, preferred within a range of the molar ratio of aluminium and chlorine from 1.9 to 2.1 to 1.

As terpenoids which can be prepared into the complex compound with aluminium hydroxychloride, h'ydroxycitronellal, icyclamen aldehyde, 1methanol, genaniol, geranyl acetate, linalool, and methyl ionone may be mentioned. Hydroxycitronellal is, however, most preferred from a viewpoint of economy and productivity.

The process of the present invention will be further explained in detail hereinbelow by giving several examples.

EXAMPLE 1 Preparation of complex compound of aluminium hydroxychloride and hydroxycitronellal g. of aluminium hydroxychloride is dissolved in 100l g. of water to give a 50 percent aqueous solution. 30 g. of hydroxycitronellal and 100 g. of methanol are added in this order to the aqueous solution to give a homogeneous solution. The solution thus obtained is heated under reduced pressure of 60 to 100 `mm. Hg

to a temperature of 60 to ,100. C. to remove the solvent methanol, lte'red, added with 300 yto 400ml. of acetone, f precipitated, filtered, nwashed with acetone yto remove unreacted hydroxycitronellal, andjthen dried, at 60"y C. for

l0. half an hour to *giverV thedesiredornplexcompound. f The thus obtained 'product,in' which"aluminium hy product thus# obtained was then dissolved 1n absolut-eethdroxychloride ,and hydroxycitronellal rare combined v iur a molar ratio of about 5.4:1', hasttheV following compoVsi-"pY tion: l

A1 21.4 lzo -i... 'fl-D'Llgy Cl j V i H2O (boundrwater) 22,6 `Hydroxycitronellal f f 12.6

Foundepercentf rUpon `comparison of the solubility.V ofiY the complex;

YTABLE 1f" Solubility of the complex compound of aluminium i hydroxychloride and hydroxycitronellal Solvent: Solubility (wt. percent) Methanol Not less than 50.

Ethanol Not less than 50.

Seo-butanol 3.5. Propylene glycol 6.0. Glycerine 1.0. N,Ndimethylformamide 3.0.

EXAMPLEy 2 Preparation of a complex compound of aluminium hydroxychloride and cyclamen aldehyde 50 g. of aluminium hydroxychloride was dissolved in 50 g. of water and 30 g. of cyclamen aldehyde Ywas added to the solution. 250 g. of ethanol was then added to give compound ,in Yabsolute ethanol `*and that of yaluminium hydroxychloride, it will kbe seen fromTablel thatthe complex compound is dissolved in'higher than 50%, while aluminium hydroxychloride is ydissolved in less than 1%ijg f a homogeneous solution. The solution was then heated to to 80 C. under reduced pressure of 60 to 100 mm. Hg; to remove the solvent, and the product thus obtained was then dried and pulverized. The powdered product.

with a light brownish color thus obtained was then `dissolved in absolute ethanol in a concentration higher than 50 percent.

EXAMPLE 3 Preparation of a complex compound of aluminium hydroxychloride and geranyl acetate 50 g. of aluminium hydroxychloride Was dissolved in 4 EXAMPLE-1 Preparation ,of a-complex compound of aluminium f jhydroxychloride and geraniolV l r5.0. g. ofalurninium hydroxychlorideY was dissolved in` n l 80l gfof water-and 30': g, of geraniolwas addedy to the l solution. g. of ethanol was further added; to give a homogeneous solution.Y The solution was heated under reduced pressure to remove the solvent andthe productV i thusobtained was driedy and'pulverized to give aV powtiered product with Va light yellowish color. The powdered 'anoljin a concentration higher thanL 30 percent.

Exam-LE. 5

`Preparation of a complex compound ofalurniniurn jfhyd'roxychloride and 1menthol K.

"50 ggoaluminium hydroxychloride was dissolved in `50`g."ot water and 30V g. of l-mentholY was added to the ksolution Then, 100 Vg. ofethanolwas:further added to .L Y l provideY a homogeneous solution. The solution thusI obf n ytained was heated underreducedpressure tov-.remove theV f solvent'and the product was then dried andpulverized to ,a1powd'ered` product with a whitejcolonflhe powdered productwas then dissolvedV in absolute 'ethanol in a con-Y centration higher than 40 percent. This complex com-,- Q pound is soluble in absolute alcohol and is, therefore,

convenient for the preparation of aerosol antiperspirants. The typical formulation of an aerosol using the complex compound of the present invention is given below. It is to be noted that the following is a representative example only and is not intended for the limitation of the present invention.

EXAMPLE 6 (Wt. percent) Complex compound of aluminium hydroxychloride and hydroxycitronellal (product of Example l) 7.0 Ethylene oxide and oleic alcohol ester phosphate (Crodafos N-lOA available from Croda Nippon Ltd., Japan) 1.0 Oleic alcohol 1.0 Isopropyl millistate 1.0 Silicone oil 0.6 Ethanol 39.2 Trichloromonouoromethane 15.0 Dichlorodiuoromethane 35.0 Perfume 0.2

Total 100.0

The aerosol antiperspirants having the above formulation was filled in an aluminium can with no coating applied to its inner surface, and an accelerated storage test was carried out at 45 C. for a time interval of 3 months. Pinhole corrosion was not observed and there was no appreciable change in odor. A comparableY aerosol product prepared under the same condition and formulation but with use of marketed complex compound soluble in absolute alcohol and consisting of aluminium hydroxychloride and propyrene glycol was put to an accelerated storage test which was continued at 45 C. for an interval of 3 months. It was observed that'82 percent of the tested products suffered from pinhole corrosion and these products were found to be unmarketable.

What is claimed is:

1. A process for the preparation of a complex compound of aluminum hydroxychloride and a terpenoid selected from the group consisting of hydroxycitronellal, cyclamen aldehyde, geraniol, linalool, geran'yl acetate and l-menthol, characterized in that l to 12 moles of aluminum hydroxychloride are reacted with l mol of said terpenoid.

2. An antiperspirant composition comprising a complex compound comprising from 1 to 12 moles of aluminum hydroxychloride and 1 mole of a terpenoid selected from the group consisting of hydroxy citronellal, cyclamen, aldehyde, geraniol, linalool, geranyl acetate and l-menthol.

3. A composition of claim 2 wherein the complex compound comprises about 5.4 moles of aluminum hydroxy chloride and one mole of hydroxycitronellal.

4. A composition of claim 2 wherein the complex compound comprises aluminum hydroxychloride and cyclamen aldehyde. l

5. A composition of claim 2 wherein the complex compound comprises aluminum hydroxychloride and geranyl acetate.

6. A composition of claim 2 wherein the complex compound comprises aluminum hydroxychloride and geraniol.

7. A composition of claim 2 wherein the complex compound comprises aluminum hydroxychloride and 1men thol.

References Cited UNITED STATES PATENTS 2,155,961 4/ 1939 Trowell 260-448 R 2,568,599 9/1951 Weidlich et al. 260--448 R X 3,287,223 11/ 1966 Theile et al. 424-68 FOREIGN PATENTS 874,164 8/1961 Great Britain 260-488 AD WERTEN F. W. BELLAMY, Primary Examiner U.S. Cl. X.R. 424-68 

